Machine for forming flat coils of wire



June 27, 1950 F. A. GENUA MACHINE FOR FORMING FLAT COILS 0F WIRE Filed Jan. 18, 1949 3 Sheets-Sheet 1 mmvron: FRANK A. GE/VUA ATTX June 27, 1950 F. A. GENUA MACHINE FOR FORMING FLAT COILS OF WIRE 3 Sheets-Sheet 2 Filed Jan. 18, 1949 INVENTORY FRANK A. GE/VUA ATTX June 27, 1950 F. A. GENUA MACHINE FOR FORMING FLAT COILS 0F WIRE 3 Sheets-Sheet 5 Filed Jan. 18, 1949 INVENTOR.

fRANK A. GENUA Patented June 27, 1950 MACHINE FOR FORMING FLAT COILS WIRE Frank A. Genua, Waterbury, Conn.

Application January 18, 1949, Serial No. 71,510

2 Claims. (Cl. 15364) This invention relates to machines for makin fiat coils of wire, and more particularly to a machine adapted to wind spring or other resilient wire into coils having accurately formed and aligned outside turns which are located in parallel planes.

One object of this invention is to provide a machine of the above nature in which the coil is formed by overbending the successive turns about a mandrel whereby the inherent resilience of the wire will cause the opposite sides of the coils to lie substantially in parallelism.

Another object is to provide a machine of the above nature wherein the coil forming mandrel is recessed so as to permit the turns of the wire to be pressed further inwardly than their final position by a pair of opposed dies, and thus ac quite the desired set. v

Another object is to provide a machine of the above nature wherein excessive overbending of the wire is prevented by means of an inner abutment which is provided by a central web sectio of the mandrel.

A further object is to provide a machine of the above nature which will be simple in construction, inexpensive to manufacture, easy to install and operate, compact, and very efficient and durable in use.

With these and other objects in view, there has been illustrated on the accompanying drawing one form in which the invention may conveniently be embodied in practice.

In the drawings,

Fig. 1 is a front view of the improved machine showing the dies in separated position.

Fig. 2 is a front view of a portion of the same, on an enlarged scale, showing the dies in their inner position, and pressing the wire upon the mandrel.

Fig. 3 is a perspective view of the same, but showing the dies in separated position.

Fig. 4 is a right hand side view of the machine, partly broken away.

Fig. 5 is a view of the intermittent drive mechanism for the mandrel, taken substantially on the line 5*5 of Fig. 4.

Fig. 6 is a fragmentary cross-sectional view, taken substantially on the line li -6 of Fig. 4, showing the gearing and the anti-backlash mechanism.

Fig. '7 is a plan View of the machine, partly broken away.

Fig. 8 is a fragmentary rear view of the same, showing the stop mechanism for the mandrel.

Fig. 9 is a perspective view of a portion of the finished coil of wire.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral It! indicates a recessed mandrel having a flat central web section I! which has opposite enlarged parallel rounded edge portions l2, whereby a cross-section of the mandrel resembles the shape of a dumbbell (Fig. 2). v

The mandrel Ill is mounted upon the forward end of a horizontal shaft l3 which is journaled in the upper central portions of front and rear walls I4, I5, of a U-shaped frame l6, and. is adapted to be intermittently rotated so as to wind wire W into a flat-sided coil C on said mandrel.

The mechanism for rotating the shaft l3 corn prises a pair of mutilated gears l1, [8 (Fig. 52 secured respectively on the horizontal shaft J3 and on a drive shaft 19 which is carried in the front and rear walls l4, l5 below the horizontal shaft l3. The drive shaft l9 extends outwardly of the rear wall I5 and carries a pulley 2B, which is adapted to be engaged by a belt driven from any suitable source of power, not shown.

The mutilated gear I! is provided with a pair of diametrically opposed toothless segments 2|, 2| whereas the lower mutilated gear l8 has a single toothless segment 22 extending over ap-, proximately one-half of its circumference, so that when the drive shaft I9 is constantly rotated, the upper shaft l3 will be driven in successive steps of degreeseach, withdwell periods be. tween the steps. 3

In order to cause the'teeth of the upper gear H to engage with the teeth of the lower gear H! for initiating each step of the rotation, the upper gear I! ,is provided with a pair of Side pins 23, 23 disposed adjacent the respective toothless segments 2| and in such a position as to be engaged by a dog 24 secured to the lower gear Ill.

The side pins 23 are arranged in the same plane as the recessed mandrel in so that when said mandrel is rotated to a vertical position, the driving connection between the multilated gears ll and I8 will be broken and will remain broken until the lower gear l8 has made another halfrevolution so as to bring the dog 24 into engagement with one of the side pins 23, and thus initiate another half-re'volution of the mandrel Ill.

In order to prevent the mandrel Ill from moi ing pasta vertical position at "the beginning of each dwell period, provision is made of a stop mechanism comprising a cam 25 (Fig; 8), which is secured upon the shaft l3 outwardly of the rear wall Hi. The cam has a pair of diametrically opposed recesses 26 which are adapted to be engaged by a roller 21 carried by an inclined springpressed plunger 28, which is slidably mounted in a bracket 29 on the rear wall l5. The stop cam 25 is so adjusted with relation to the shaft [3, as to prevent overriding of the upper mutilated gear I I when the latter comes to its dwell position.

However, when the driving connection between the gears l1, pressed plunger 28 will yield so that the roller 21 may ride out of the recess 26 in which it is disposed, and thus permit the stop cam 25 to resume rotation.

In order to insure against backward rotation of the mandrel in during the dwell period, pro.- vision is made of an anti-backlash cam 30 (Fig. 6) secured to the shaft l3 inwardly of the rear wall l5. The cam 30 is provided with a pair of diametrically-opposed radial steps 3|, 3| adapted to be intermittently engaged by a pawl 32 which is mounted on a stationary pivot 33 and which is urged against the periphery of said cam by means of a spring 34. I

v The radial steps 3! are so disposed with relation to the shaft I3 that the pawl 32 will drop against one of said steps at the same instant that the mandrel l0 arrives at a vertical position, thus preventing any backward movement of said mandrel.

The machine is so constructed that the wire W will approach the recessed mandrel ID in a path which is substantially tangent to said mam drel, said wire being guided by means which comprises a forwardly-projecting bracket 35 (Figs. 1, 4, and 7) secured to the top center portion of the front wall l4, and a horizontally-adjustable slotted guide 36 secured to the front face of said bracket by means of a clamping screw 31. v

The wire W is slidably confined between a reduced inner end portion 38 (Fig. 3) of the guide 36 and the front face of the bracket 35, said front face being disposed in substantially the same plane as the front end of the shaft l3.

.The bracket 35 is also provided with a screw having an apertured head 39 which serves as a guide for the wire W prior to its entrance between the reduced guide portion 38 and the bracket 35.

1 The machine may be further provided, if desired, with an additional guide 40 which is secured to a post 4| on the front wall Hi.

In order to slide the .coil C progressively 'off from the mandrel ID as new turns of wire are formed thereon, provision is made of a slotted cam piece 42 which is adjustably secured to the front of the bracket 35 by meansof a clamping screw 43. The lower end of the cam piece 42 has an integral inclined stripper tongue 44 which has a camming action against each new turn of the wire as itis rotated upon the mandrel It, thus urgingit outwardly of said mandrel.

In order to impart a 180 degree set to the wire W about the enlarged edge portions l2 of the mandrel l0, provision is made of a pair of opposed reciprocating dies 45, 45 (Fig. 2) which have narrow end faces 46 for pressing each new turn of wire into the recessed sides of the mandrel l0 during each dwell period of said mandrel; Thus, it will be seen that the wire will be bent more than 180 degrees about the enlarged edge portions 12 to produce a permanent set of the wire of 180 degrees, so that the sides of I8 is reestablished, the spring- 4 the coil C will be perfectly flat when released by the dies 45.

The dies 45 are preferably operated by means of a pair of horizontal rectangular supporting slides 41, 41 carried in aligned horizontal guideways 48, 48 in a pair of brackets 49, 49 which are secured to the upper and outer portion of the front wall 14, a plurality of retainer plates 50, 50 being provided forholding the slides 41 in position.

The slides 4'! have vertical slots 5|, 5| formed in their inner faces, said slots being engaged with eccentric pins 52, 52 upon the forward ends of a pair of horizontal upper shafts 53, 53 which are supported in the front and rear walls I4, l5 (see Fig. 4). Thus, rotation of said shafts 53 will reciprocate the slides 41 and the dies 45 thereonthe pins 52 being so arranged that the dies 45 will move toward each other so as to simultaneously engage the wire at the opposite sides of the mandrel l0.

The shafts 53 are provided with a pair of gears 54, 54 which are connected with a gear 55 on the drive shaft l9 by means of a pair of idler gears 56, 56 supported on a pair of lower shafts 51, 51.

It will be understood that the operating mechanism for the dies 45 is so proportioned and adjusted as to cause said dies to engage a new turn of wire upon the mandrel I0 during each dwell period in the rotation of said mandrel, thus insuring that each successive turn of the wire in the coil C will receive the proper set.

Operation In operation, the leading end of the wire W will first be inserted in the guides 46 and 39 and between the adjustable guide 36 and the bracket 35, and then engaged with the mandrel In, as for example by bending one turn of the wire manually about said mandrel. The drive pulley 20 will then be driven from any suitable source of power so as to rotate at a substantially constant speed in clockwise direction, as viewed in Fig. 1.

This will cause the recessed mandrel ID to rotate counterclockwise in a series of degree steps having interposed dwell periods during which the mandrel I0 will be disposed in a vertical position, as seen in Fig. 1.

During each of the dwell periods, the dies 45 will approach the mandrel III, as hereinbefore described, so as to press the sides of the newly formed turn of Wire into the recessed sides of the mandrel 10 adjacent the web section II. The dies 45 will then separate, so as to permit another 180 degree movement of the mandrel l0, after-which the movement of the dies 45 will be repeated.

Each new turn of wire will, of course, come into engagement with the stripper tongue 44 at each movement of the mandrel In, so that the colic will be progressively urged off the mandrel l0, and each new turn of wire will be formed accurately in position to be engaged by the die faces 46.

The aforesaid operation will result in a coil having accurately formed parallel fiat sides joined by opposite semi-circular edge portions.

It will be seen that the action of the dies 45 will bend the wire more than 180 degrees around the enlarged edge portions I2 of the mandrel Ill, thus overbending the wire to a predetermined extent and yet permanently setting the wire in a bend of only 180 degrees.

Although slight reverse bends in the wire will occur adjacent the edges of the dies 45 during manufacture, as shown in Fig. 2, these reverse bends are attended by no strain beyond the elastic limit of the wire, and disappear as soon as the dies 45 are withdrawn.

The operation of the machine may be continued until such time as the coil C has attained the desired length, at which time it may be cut off the mandrel ill by any suitable cutting means, not shown.

While there has been disclosed in this specification, one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure, but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming Within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In a machine for forming flat-sided coils of resilient wire, a rotatable mandrel having enlarged cylindrical substantially parallel edge portions joined by a flat, solid, anvil web section providing recesses in the sides of said mandrel, wire guide means, mechanism for rotating said mandrel to wind wire from said guide means into a coil on said mandrel, and means for pressing said Wire into said recesses against said web section inwardly of said enlarged edge portions,

.whereby said wire may be overbent around said edge portions so as to receive a predetermined permanent set.

2. In a machine for forming flat coils of resilient wire, a mandrel having a pair of enlarged substantially cylindrical parallel edge portions joined by a fiat solid, anvil web section, means for winding wire over said edge portions to form a coil on said mandrel, and means for pressing the wire on said mandrel inwardly against both sides of said web section between said edge portions, whereby the wire may be bent more than degrees around each edge portion so as to receive a permanent set of 180 degrees.

FRANK A. GENUA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 426,386 Kelly Apr. 22, 1890 1,987,333 Geer Jan. 8, 1935 2,431,928 Garreau Dec. 2, 1947 2,455,549 Benjamin Dec. 7, 1948 FOREIGN PATENTS Number Country Date 649,891 France Sept. 10, 1923 

